MXPA97003111A - Form of doses molded by inyecc - Google Patents

Abstract

The present invention relates to a dosage form for delivering a therapeutic agent to an environment of use, said dosage form comprising: a) an internal compartment, b) a therapeutic composition comprising a therapeutic agent in the compartment; expandable composition comprising means for pushing the therapeutic composition from the dose form to the compartment, d) exit means in the dosage form connecting the therapeutic composition to the environment of use, and wherein the dosage form is characterized in that it comprises: e) an injection molded membrane comprising a thermoplastic polycaprolactone, said injection molded membrane is permeable to the passage of the liquid and surrounds, defines and forms the internal compartment.

Description

FORM OF DOSE MOLDED BY INJECTION FIELD OF THE INVENTION This invention pertains to dosage forms provided by injection molding principles. More specifically, the invention relates to injection molded membranes manufactured in advanced dosage forms expressed as osmotic dosage forms especially for the preoral administration of a therapeutic agent. The invention also relates to compositions comprising at least one polymer used for the injection molding of an article of manufacture.

BACKGROUND OF THE INVENTION Unique dosage forms, manufactured as osmotic distribution systems, entered the fields of medicine and pharmacy with the invention of the osmotic distribution systems of the inventors Theeuwes and Higuchi, as described in the patents of EUR Nos. 3,845,770 and at 3,916,899. The osmotic systems described in these patents comprise a semipermeable membrane surrounding a compartment containing a therapeutic agent. The membrane is permeable to the passage of an external liquid, and is substantially impermeable to the passage of the drug. There is at least one exit through the membrane for the distribution of the therapeutic agent from the osmotic dose form. One of the first advances in osmotic distribution systems in assortment techniques was presented in US Patent No. 4,327,725 by the patentees 5 of the Cortese and Theeu patent. This invention provides an osmotic distribution system for the distribution of a therapeutic agent which, due to its solubility in aqueous and biological liquids, is difficult to distribute in significant amounts at a controlled rate over time. ± os of osmotic distribution of this patent comprises a semipermeable wall surrounding a compartment containing a therapeutic agent that is insoluble to highly soluble in aqueous and biological liquids, as well as an expandable hydrogel. When working, the hydrogel expands in the presence of a liquid The external agent is contained in the distribution system and pushes the therapeutic agent from the distribution system, through an exit route. A further contribution to distribution techniques is an inventive distribution system described in the patent US No.5,023,088 by the holders of the Uong patent, Theeuwes, Ec enhoff, Larsen and Huynh. In this patent, the patentee described a distribution system comprising a semipermeable housing component having a housing containing a plurality of units. movable therapeutics. The patentees further described a dynamic component for the displacement of the therapeutic units through an open orifice formed in the housing components, when the distribution system operates in an environment of use. It will be appreciated by those skilled in the art of assortment, that the dosage forms described above have a positive inventive value and represent a practical and useful advance in the assortment technique. Also, while the dosage forms described above possess ideal kinetic useful for distributing numerous and different drugs and at a controlled and continuous rate in many environments of use, there is a case where the manufacturer of these dosage forms can be perfected to obtain more convenient results.

For example, the dosage forms of the prior art are manufactured by a membrane coating process, wherein an organic solvent such as acetone or methylene chloride is used to cover the membrane in the dosage form. Even though these solvents form excellent membranes, there are serious deficiencies associated with their use. That is to say, these organic solvents are expensive, they are explosive, the traces can be possibly toxic and during the processing fumes of the solvent can escape and cause environmental problems. The conditions necessary to optimize production to produce a thin or thick membrane often become impractical in mass production, because the variability between the weight and the uniformity in the thickness of the membrane can cause differences in the release profiles of the dosage form. In addition, the optimization of the coating conditions is very expensive in each successive scale of the layer and the production of a thick membrane often becomes impractical in mass production due to the extremely long coating time. In addition, some special membrane shapes may not be manufactured by the coating process due to their complex geometry. It will be appreciated by those skilled in the art of xti assortment, that if a dosage form can be provided that exhibits a high level of activity of reliable assortment and is manufactured by a process that overcomes the deficiencies and disadvantages associated with the prior art, said form of dose and its accompanying manufacturing process would have a positive value and would also represent a breakthrough in the technique of suri ido. It will also be immediately appreciated by those skilled in the art of assortment that if it is a designed dose form or an osmotic dosage form essentially free of organic solvents, said dosage form would find an application practice in the fields of pharmacy and medicine. Likewise, it will be appreciated by those skilled in the art that if a new composition for injection molding is provided which reduces the problems known up to now, said composition would represent an advance positive in the technique.

OBJECTIVES OF THE INVENTION Accordingly, in view of the above presentation, it is an immediate object of this invention to provide a dosage form designed as an osmotic system that can be manufactured by normal manufacturing techniques that overcome the deficiencies and disadvantages known in the prior art. Another object of the invention is to provide a dosage form designed and manufactured essentially free of organic solvents. Another object of the invention is to provide an injection molding process for the manufacture of membranes for dosage forms that can be used in commercial mass production. Another object of the invention is to provide membranes manufactured by injection molding processes, wherein the membrane possesses water permeability, is substantially impermeable to a therapeutic agent and possesses mechanical properties useful for the manufacture of an osmotic dose form. Another objective of the invention is to provide a useful composition for injection molding items in medicine and health. Another object of the invention is to provide a composition with thermoplastic properties.

Another object of the invention is to provide a composition comprising at least one polymer, whose composition is capable of being injection molded in any desirable manner, preferably as a housing member of a dosage form. Another object of the invention is to provide a composition comprising two or more polymers useful for the thermoplastic molding thereof. Other objects, features, aspects and disadvantages of this invention will be more apparent to those skilled in the art of assortment from the following detailed specification taken in conjunction with the accompanying claims.

DETAILED DESCRIPTION PF THE TNVFNHT? N In accordance with the mode and manner of this invention, new compositions are provided for injection molding into membranes, which are molded into dosage forms. The compositions comprise a thermoplastic polymer, or the compositions comprise a blend of thermoplastic polymers and optional ingredients for injection molding. The thermoplastic polymer that can be used for the present purpose comprises polymers having a low softening point, for example, lower than 200 ° C, preferably within the range of 40 ° C to 180 ° C. The polymers are preferably synthetic resins, for example, linear polycondensation resins, polyacrylated condensation resins, polyacrylated addition resins, co or polyamides, resins obtained from primary diepoxides and alkanolanes, glycerin resins and phthalic anhydrides, polymethane, polyvinyl resins, polymer resins with free or esterified carboxyl or carboxamide groups, for example with acrylic acid, acrylic amide or esters of acrylic acid, polycaprolactone, and their copolymers with dilactide, diglycolide, valerolactone and decalactone, a composition of resin comprising polycaprolactone and polyalkylene oxide, and a resin composition comprising polycaprolactone, a polyalkylene oxide such as polyethylene oxide, poly (cellulose) such as poly (hydroxypropylcellulose), poly (hydroxyethyimethylethylcellulose),? oli (hydroxyethylcellulose) , and poly (hydroxypropylcellulose). The membrane forming composition can comprise optional membrane-forming ingredients, co or polyethylene glycol, talc, polyvinyl alcohol, lactose or polyvinyl pyrrolidone. The compositions for the formation of a polymer composition for injection molding can comprise 100% thermoplastic polymer. The composition in another inclusion comprises 10% to 99% of a thermoplastic polymer and 1% to 70% of a different polymer, the total being equal to 100%. The invention also provides a thermoplastic polymer composition comprising 1% to 98% of a first thermoplastic polymer, 1% to 90% of a second different polymer and 1% to 90% of a third distinct polymer, all polymers being equal to 100%. Representative composition comprises 20% to 90% of terpeneplastic polycaprolactone and 10% to 80% of alkylene poly-oxide); a composition comprising 20% to 90% polycaprolactone and 10% to 60% poly (ethylene oxide), the ingredients being equal to 100%; a composition comprising 10% to 97% polycaprolactone, 10% to 97% poly (alkylene oxide) and 1% to 97% poly (ethylene glycol), all ingredients being equal to 100%; a composition comprising 20% to 90% polycaprolactone and 10% to 80% poly (hydroxypropylcellulose), all ingredients being equal to 100%; and a composition comprising 1% to 90% polycaprolactone, 1% to 90% oly (ethylene oxide), 1% to 90% oly (hydroxypropylcellulose) and 1% to 90% poly (ethylene glycol), all ingredients being equal to 100%. The percentage expressed,%, is percent by weight,% by weight. In another embodiment of the invention, a composition for injection molding to provide a membrane, is prepared by mixing a composition comprising 63% by weight of polycaprolactone, 27% by weight of polyethylene oxide and 10% by weight of polyethylene glycol in one conventional mixing machine, such as a Moriyama Mixer at 65 ° C to 95 ° C, adding the ingredients to the mixer in the following addition sequence, polycaprolactone, polyethylene oxide and polyethylene glycol. All the ingredients were mixed for 135 minutes at a rotor speed of 10 to 20 rpm. The mixture was then fed to a Baker Perkins Kneader® extruder at 80 ° C to 90 ° C, at a pumping speed of 10 rpm and at a worm speed of 22 rpm, and then cooled to 10 ° C at 12 ° C until reaching a uniform temperature. Then, the cooled extruded composition was fed to an Albe Pelletizer, pelleted at 25 ° C and at a length of 5 m. The pellets were then fed to an injection molding machine, an Arburg Allrounder at 93 ° C at 177 ° C, heated to a molten polymeric composition and the liquid polymeric composition was forced into a mold cavity at high pressure and speed until that the molding will be filled and the composition comprising the polymers will solidify in a pre-selected conformation. The parameters for injection molding consist of a band temperature through zone 1 to zone 5 of the barrel, from 91 ° C to 191 ° C, an injection molding pressure of 1818 bar, a speed of 55 crna / s and a melting temperature of 75 ° C. The phrase "therapeutic agent and drug" is used herein reciprocally, and refers to an agent, pharmacological compound, composition of matter or mixture thereof that provides a therapeutic effect, often beneficial. This includes pesticides, herbicides, germicides, biocides, algicides, rodenticides, fungicides, insecticides, antioxidants, plant growth promoters, plant growth inhibitors, preservatives, antipreservatives, disinfectants, sterilization agents, catalysts, chemical reagents, agents fermentation, food, food supplements, nutrients, cosmetics, 5 drugs, vitamins, sexual sterilizers, fertility inhibitors, fertility promoters, attenuators of microorganisms and other agents that benefit the environment of use. As used herein, the terms also include any substance physiologically or pharmacologically i. active that produces a systemic or localized effect or effects on animals, including warm-blooded mammals, humans and primates; birds; domestic or farm animals such as cats, dogs, sheep, goats, cattle, horses and pigs; laboratory animals such as mice, rats and guinea pigs; fishes; reptiles, wild and zoo animals, and the like. The active drug that can be released includes organic and inorganic compounds, including, without limitation, drugs that act on peripheral nerves, adrenergic receptors, cholinergic receptors, muscle skeletal systems, the cardiovascular system, smooth muscles, the blood circulatory system, synoptic sites, nephrotector binding sites, endocrine and hormonal systems, the uniological system, the reproductive system, the skeletal system, the autocoid systems, the systems food and excretory, the histarnma system, and the central nervous system. Appropriate agents can be selected from, for example, proteins, enzymes, hormones, polynucleotides, nucleoprotemes, polysaccharides, glycoproteins, M-lipoproteins, polypeptides, steroids, hypnotics and sedatives, psychic exciters, tranquilizers, anticoagulants, muscle relaxants, antiparkinson agents, analgesics. , anti-inflammatories, local anesthetics, muscle contractants, anti-microbial agents, antimalarials, hormonal agents that include contraceptives, sympathomrometics, polypeptides and proteins capable of producing physiological effects, diuretics, lipid regulating agents, antiandrogenic agents, antiparasitic agents, neoplastic agents, antineoplastic agents, hypoglycemic agents, agents and nutritional supplements, supplements for growth, fats, ophthalmics, antieteritic agents, electrolytes and diagnostic agents. Examples of beneficial agents that can be used with this invention are prochlorperazide edisilate, ferrous sulfate, arninopepoic acid, mecaxilarnin hydrochloride, procamamide hydrochloride, amphetamine sulfate, methamphetamine hydrochloride, benzfetarrun hydrochloride, isoproterol sulfate, fenmetran sulfate, phenmetrazma hydrochloride, bethanechol chloride, methacholine chloride, pilocarpma hydrochloride, atropine sulfate, scopolamine bromide, isoproparnide iodide, tpdihexetii chloride, phenforrnin hydrochloride, rnetylphenidate hydrochloride, theophylline colmate, cephalexin hydrochloride, diffe , eclizine hydrochloride, prochloroperazine maleate, phenoxybenzarnine, thietylperazine rnaleate, anisindone, diphenadione, erythritil tetranitrate, digoxin, isoflurophate, acetazolamide, rnetazolarnide, bendroflumethiazide, chloroproparnide, tolazarnide, chloradninone acetate, fenaglycodol, allopurinol, aluminum aspirin, rnetotrexate, acetyl sulfisoxasol, erythrornicine, hydrocortisone, hydrocorticosterone acetate, cortisone acetate, dexamethasone and its derivatives such as betamethasone, triamcinolone, rnetiltestosterone, 17-ß-estradiol, ethinyl estradiol, ethinylestradiol 3-methyl ether, prednisolone, acetate 17- β-hydroxyprogesterone, 19-norprogesterone, norgestrel, norethindone, norethisterone, noretiederone, progesterone, norgesterone, norethisterone, norethynodrel, aspirin, indoethacin, naproxen, fenoprofen, sulindac, indoprofen, nitroglycerin, isosorbide dinitrate, propanonol, timolol, atenolol, alprenolol , cirnetidine, clonidine, and iprarnine, levodopa, chloropromazine, methyldopa, dihydroxyphenylalanine, theophylline, calcium gluconate, ketoprofen, ibuprofen, cephalexin, erythrornicin, haloperidol, zomepirac, ferrous lactate, vincamine, diazepa, phenoxybenzamine, diltiazern, milrinone, captropil, mandol , quabenz, hydrochlorothiazide, ranitine, flurbiprofen, fenbufen, fluprofen, tolmetin, alclof enac, mefenamic acid, flufenamic acid, difuninal, nimodipine, nitrendipine, nisoldipine, nicardipine, felodipine, lidoflazine, tiapa il, gallopamil, a lodipin, ioflazine, lisinopril, enalapril, captopril, ramipril, endlapriat, farnotidine, nizatidine, sucralfate, etindinine, tetratolol, minoxidil, chlorodiazepóxido, diazepa, to itriptilina and irnipramina. Other examples are proteins and proteins that include, but are not limited to, insulin, colchicine, glucagon, thyroid stimulating hormone, parathyroid and pituitary hormones, calcitonin, renin, prolactin, corticotrofrine, thyrotropic hormone, follicle-stimulating hormone, chorionic gonadotropin, porcine somatotropin, oxytocin, vasopressin, prolactin, atostina, lyserin, pancreozimine, luteinizing hormone, LHRH, interferons, interleukins , growth hormones with human sornatotropin, bovine somatotropin and porcine somatotropin, fertility inhibitors or prostaglandins, promoters of fertility, growth factors and human pancreatic hormone release factor. It should be understood that more than one therapeutic agent may be incorporated in the dosage form of this invention, so that the use of the terms "therapeutic agent" or "drug" in no way precludes the use of two or more of said therapeutic agents or drugs. The therapeutic agent can be in a wide range of chemical and physical forms, such as uncharged molecules, components of molecular complexes, non-irritant pharmaceutically acceptable salts, therapeutic derivatives of the therapeutic agent such as ethers, esters, amides, etc., therapeutic derivatives of the therapeutic agent that are easily hydrolyzed by the pH of the body, and enzymes, and are included in this invention. The amount of therapeutic agent in the dosage form is an amount necessary to produce the desired therapeutic response. In practice, this will vary widely, depending on the particular therapeutic agent, the site of distribution, the severity of the medical condition, and the desired therapeutic effect. Thus, it is often not practical to define a particular therapeutic scale for a therapeutically effective dose of the active therapeutic agent incorporated in the dosage form.; however, the dosage form will generally contain 10 ng to 2.5 g of the therapeutic agent. Therapeutically active drugs are described in h rmaco-th rap. Vol. 8, pp 147-157 (1988); ÜHÍS? U. Vol. 30, pp 333-354, (1985); Reminqton's Pharmacoloa. lime Basis of Theraoeutics by Goodman and Gilman 4th Ed., 1970 published by The Man Million Company, London. The term osmagent, as used herein, also includes osmotically effective solute, osmotically effective compound and osmotic agent. The osmotically effective compounds that can be used for the purpose of this invention include inorganic and organic compounds that exhibit an osmotic pressure gradient across a semipermeable membrane against an external liquid. Osmotically effective compounds useful for the present purpose include magnesium sulfate, magnesium chloride, sodium chloride, lithium chloride, potassium sulfate, sodium carbonate, sodium sulfate, lithium sulfate, potassium chloride, sodium sulfate, calcium bicarbonate, calcium sulfate, potassium acid phosphate, calcium lactate, mannitol, urea, inositol, magnesium succinate, tartaric acid, 5 carbohydrates, raffinose, sucrose, glucose, lactose monohydrate and mixtures thereof. The osmotically effective solute can be in any physical form such as particle, crystal, pellet, tablet, strip, spray, film or granules. Osmotically effective solutes and methods for the? T) measurement of osmotic pressures are described in the U.S. Patent. No. 5,232,705. The thrust composition contains an expandable medium also known as the opolomer or hydrogel, and the expandable component in the dosage form for the purpose of this The invention comprises a thrust composition that interacts with water or aqueous biological liquids, and swells or expands to a state of equilibrium. Osmopolymers exhibit the ability to swell in water and retain a significant portion of the water included within the structure of the polymer. The osmopolymers swell or expand to a very high degree, often exhibiting or increasing in volume from 2 to 50 times. The osmopolymers may or may not be interlaced. The inflatable hydrophilic polymers are, in a presently preferred inclusion, slightly interlaced, such as transverse bonds that are formed by covalent or ionic bonds. The osmopolymers may be of vegetable, animal or synthetic origin. Suitable hydrophilic polymers for the present purpose include poly (hydroxyalkyl methacrylate), which has a molecular weight of 30,000 to 5,000,000; poly (vinylpyrrolidone), which has a molecular weight of 10,000 to 360,000; anionic and cationic hydrogels; polyelectrolyte complexes, polyvinyl alcohol), which has a low acetate residue, entangled with formaldehyde or glutaraldehyde, and which has a degree of polymerization of 200 to 30,000; a mixture of rilethylcellulose, crosslinked agar and carboxymethylcellulose, a water-swellable, water-insoluble copolymer produced by forming a dispersion of finely divided copolymer of malic anhydride with styrene, ethylene, propylene, butylene or isobutylene entangled with 0.0001 to about 0.5 moles of polyunsaturated crosslinking agent per mole of aminic anhydride in the copolymer; water-swellable N-vinyl lactide polymers, and the like. Other osmopolymers include polymers that form hydrogels such as Carbopol * acid carboxypolymers, which generally have a molecular weight of 450,000 to 4,000,000; the sodium salt of Carbopol® acidic carboxypolymers and other metal salts; polyacrila idas Cyana er *; interlaced polymers of water-swellable indene malic anhydride; Goodrite® polyacrylic acid having, but not limited to, a molecular weight of 80,000 to 200,000, and the salts of sodium and other metals; Polyox® polyethylene oxide polymers having a molecular weight of 100,000 to 7,800,000; graft starch copolymers; Aqua-Keeps® acrylate polymers; interlaced diester polyglycan, and the like. Representative polymers that form hydrogels are known in the prior art in the U.S. Patent. No. 3,865,108 issued to Hartop; Patent of E.U.A. No. 4,207,893 issued to Michaels, and in Handbook or Co mon Pplyrner, by Scott and Roff, published by the Chemical Rubber, CRC Press, Cleveland, OH. Other osmopolymers that may be present in the first layer ifl include agarose, alginates, ilopectin, arabinogalactan, carrageenan, eucheuma, fucoidan, furcellaran, gelatin, guar gum, agar gum, gum arabic, ghatti gum, karaya gum, gum tragacanth, hypnea, laminariña, locust bean gum, pectin, polyvinyl alcohol, polyvinyl pyrrolidone, propylene glycol alginates, N-vinyl lactam polysaccharides, xanthan gum, and the like. Osmopolymers are known in Controlled Relay Sys em. Fabrication Technology, Vol. II, pg 46 (1988), published by CRC Press, Inc. The composition comprising a therapeutic agent for use in the invention is obtained by normal manufacturing techniques. For example, in a manufacture, a therapeutic agent is mixed with composition forming ingredients, and then 3β is subjected to pressure in a solid configuration corresponding to the internal dimensions of the space within the dosage form. In another inclusion, the therapeutic agent and another composition form ingredients and are mixed in a solid or in an isolide, by conventional methods, such as ballmilling, satin, stirring or rolling, and then pressurized into a preselected layer obtaining the configuration . A thrust expansion composition comprising an osmopolymer is prepared in a similar manner, and subjected to pressure in a configuration that corresponds to the internal composition of the dosage form. The methods for preparing the composition of a therapeutic agent, as well as the composition of an osmopolymer, are described in the U.S. Patent. No. 5,024,843. The following examples are illustrative of the present invention, and should be considered as in no way limiting the scope of the invention, since these examples and other equivalents thereof will be apparent to those skilled in the art in light of the present disclosure and the attached claims. A dosage form comprising an injection molded membrane consisting of the composition of polycaprolactone, polyethylene oxide and polyethylene glycol surrounding an internal space with an open mouth and a dosed bottom, is charged at its bottom with a push composition and then with a drug composition in the open mouth. The push composition comprises 58.75% by weight of sodium carboxymethylcellulose, 30.00% by weight of sodium chloride, 5.00% by weight of hydroxypropylmethylcellulose, 5.00% by weight of hydroxypropylcellulose, 1.00% by weight of red ferric oxide and 0.25% by weight of magnesium stearate. The composition of the drug comprises 66.70% by weight of ge fibrozil. , 14.30% by weight of acid-di-sol, a sodium croscarmellose, 9.50% by weight of polyethylene oxide of molecular weight 200,000, 5.00% by weight of surfactant Myrj 52-S, also known as polyethylene glycollate 40 stearate, 3.00% by weight of hydroxypropyltrilethylcellulose of molecular weight 9,200, 1,000% by weight of cab-O-sil, a colloidal silicon dioxide, and 0.50% by weight of magnesium etherate. The open mouth of the dosage form is folded to an orifice of 15 thousand (0.381 nm) to provide an osmotic dosage form. A dosage form of a prior art obtained by solvent technique is described in US Patent No. 4,327,725 issued to Cortese and Theeuwes and assigned to the ALZA Corporation. Another dosage form provided by the invention comprises a housing component consisting of a first membrane section and a second membrane section. The first section and the second section are designed to close in telescopic distribution with each other. The membrane forming the first section is injection molded from a polycaprolactone hydroxypropylcellulose composition and the second section comprises polycaprolactone, polyethylene oxide and polyethylene glycol in various proportions. The first section comprises a therapeutic composition for administration to an animal or a human. The second section is a means to obstruct the first section like a helmet during storage. The second section is medium for opening the dosage form, when the dosage form is in operation in a liquid environment that is used to supply a therapeutic composition from the first section to the environment. The second section comprises an osmotic layer comprising 58.75% by weight of sodium carboxymethylcellulose, 30.00% by weight of sodium chloride, 5.00% by weight of hydroxypropylmethylcellulose of molecular weight 9,200, 5.00% by weight of hydroxypropylcellulose, 1.00% by weight of red ferric oxide and 0.25% by weight of magnesium stearate. The osmotic layer is located against the bottom of the second section. Then, a barrier layer comprising 95.00% by weight of stearic acid and 5.00% by weight of hydroxypropylmethylcellulose of molecular weight 9,200, is located on the section forming a bilayer with the osmotic layer. The dosage form is assembled by the smaller open end adapted to the inside of the open end of the layer and together they are compressed until the first section and the second section fit tightly together. Dosage forms obtained by solvent techniques are described in U.S. Patent No. 5,312,388 issued to Wong, Theeuwes and Larsen and assigned to the ALZA Corporation. Conventional machines for injection molding, as described in En? yclo? <; 3ia of poiyrner Scien? E and, Engineering; vol. 8, Injection-Molding pages 102 to 138, 1987, may be used for the purpose of this invention.

By injection molding a dosage form having a housing component for containing the liquid formulation is obtained. The housing component comprises a semipermeable membrane that surrounds an internal compartment. The accommodation component has a wide open mouth and a closed bottom. The injection molded membrane comprises a polycaprolactone composition and a mixture derived from cellulose or polycaprolactone, polyethylene oxide and polyethylene glycol to provide a semipermeable membrane. The cellulose derivative is selected from the group consisting of cellulose ether, cellulose ester, hydroxyalkylcellulose, and hydroxypropylalkylcellulose. The dosage form is obtained by first placing at the bottom of the housing component an expandable pressure-pressed layer comprising 79.00 wt.% Of Keltone HV, sodium alginate, 15.00 wt.% Calcium sulfate, 5.00 wt.% Poly. (Vinyl? Ridolidone), 0.50% by weight of ferric oxide and 0.50% by weight of magnesium stearate. Then, a barrier layer that prevents mixing of the liquid formulation with the expandable layer under pressure is inserted into the open housing component that is in contact with the bilayer distribution. The barrier layer comprises 95.00% by weight of stearic acid and 5.00% by weight of hydroxypropylmethylcellulose. Then, the membrane that surrounds the open mouth is folded against the pressure of the air leaving a hole of 30 thousand. A liquid formulation is then injected into the folded housing component through the hole. The liquid formulation comprises 41.75% by weight of crerofor, a hydrogenated castor oil-polyoxyl 40, 35.05% by weight of corn oil, 21.97% by weight of propylene glycol, 1.10% by weight of tocopherol and 0.14% by weight of blue dye . The accompanying Figures 1 and 2 demonstrate the unexpected properties provided by the invention. In Figure 1, the permeability of a membrane comprising 63% in , weight of polycaprolactone, 27% by weight of polyethylene oxide The molecular weight 5,000,000 and 10% by weight polyethylene glycol 3350 is expressed as volume versus time. The water permeability through the membrane was measured with a saturated saline solution having an osmotic pressure II for a membrane of 20 mils in thickness (0.5 / mm), at a temperature of 37 ° C, and an area of permeability of 0.64 cm2. The permeability equation used is the following: «(c 58 25.4 u / hr atrn) = (dV / dt.) /A.II), where dV / dt-- to the slope of the graph, which is equivalent to the thickness of the membrane, A equals the permeation area and II equals the osmotic pressure of the saline solution. The accompanying figure 2 illustrates the permeability through membranes prepared by various techniques. In the scheme of Figure 2, the clear triangle illustrates the aqueous permeability through a cellulose acetate membrane comprising an acetyl content of 39.8% at changing percentages of polyethylene glycol in flow increaser in coated membranes; the clear circles show the aqueous flow through a membrane comprising polycaprolactone and polyethylene oxide of 5,000,000 molecular weight at a ratio of 70/30, with additional amounts of 3350 polyethylene glycol; and the black circles 5 denote the effects of the variable concentration of the flow enhancer on the permeability of water through membranes satinated with polycaprolactone-hydropropylcellulose. In view of the above specification comprising x preferred inclusions of the invention, it is understood that variations and modifications may be made here, in accordance with the inventive principles described, without departing from the scope of the invention. fifteen

Claims (12)

NQVEDflP PE Lfl INVENTION CLAIMS

1. A dosage form for the distribution of a therapeutic agent to an environment of use, wherein the dosage form comprises: (a) an internal compartment; (b) a therapeutic composition comprising a therapeutic agent in the compartment; (c) an expandable composition comprising i, means for the pressure expansion of the therapeutic composition from the dosage form in the compartment; (d) means of exit in the dosage form that communicates the therapeutic composition with the environment of use, and wherein the dosage form is characterized by: (e) an injection molded membrane 5 comprising a lower softening point at 200 ° C, permeable to the passage of the liquid that surrounds and defines the internal compartment.

2. The dosage form for the distribution of the therapeutic agent according to claim 1, wherein the injection molded membrane is free of solvents.

3. The dosage form for the distribution of the therapeutic agent according to claim 1, wherein the injection molded membrane has a softening point of 40 ° C to 180 ° C.

4. The dosage form for the therapeutic agent distribution according to claim 1, wherein the injection molded membrane comprises a polycaprolactone copolymer having a component selected from the group consisting of dilactide, diglycolide, valerolactone and decalactone .

5. The dosage form for the therapeutic agent distribution according to claim 1, wherein the injection molded membrane comprises a polycaprolactone and a polyalkylene oxide.

6. The dosage form for the distribution of the therapeutic agent according to claim 1, wherein the injection molded membrane comprises polycaprolactone, polyalkylene oxide and hydroxypropylcellulose.

7. The dosage form for the distribution of the therapeutic agent according to claim 1, wherein the injection molded membrane comprises a polycaprolactone and polyethylene glycol.

8. The dosage form for the distribution of the therapeutic agent according to claim 1, wherein the dosage form comprises a first section and a second section.

9. A composition comprising 20% to 90% polycaprolactone and 10% to 80% alkylene polyoxide), the composition being equal to 100%.

10. A composition comprising 10% to 97% of polycaprolactone, 10% to 97% of poly (alkylene oxide) and 1% to 97% of poly (ethylene glycol), the composition being equal to 100%.

11. - A composition comprising 1% to 90% polycaprolactone, 1% to 90% poly (alkylene oxide), 1% to 90% poly (hydroxypropylcellulose) and 1% to 90% poly (ethylene glycol), whose composition It is used for the injection molding of a membrane.

12. A composition comprising 2G% to 90% polycaprolactone and 10% to 80% oly (hydroxypropylcellulose), whose composition is useful for the injection molding of a membrane and is equivalent to 100% by weight.